Device for the planar treatment of areas of human or animal skin or mucous membrane surfaces by means of a cold atmospheric pressure plasma

ABSTRACT

The invention relates to a device, preferably a collar, for treating areas of human or animal skin or mucous membrane with a cold atmospheric pressure plasma by creating a dielectrically hindered surface discharge, comprising at least one flexible insulating material ( 1 ), a flexible high-voltage electrode ( 2 ), a flexible dielectric ( 3 ), a flexible grounded electrode ( 4 ) and a gas supply ( 7 ), characterized in that the flexible high-voltage electrode ( 2 ) is embedded in the insulating elastomer ( 3 ), having the effect of a dielectric, and the grounded electrode ( 4 ) is applied to the elastomer surface facing the surface to be treated.

The invention relates to a device for surface treatment of areas ofhuman or animal skin or mucous membrane surfaces by means of a coldatmospheric-pressure plasma. The centerpiece of the device is a specialelectrode arrangement for generating a dielectric barrier surfacedischarge, which can be applied flexibly onto arbitrarily curvedsurfaces. On the basis of this invention, it is possible to generate, inthe region of diseased skin or mucous membrane parts of the human body,in the immediate proximity of the skin or mucous membrane surface or ofwounds, a superficial plasma for treatment of diseased areas, whichplasma is safe as regards the stress on the skin or mucous membrane dueto temperature and electrical voltages.

PRIOR ART

As the result of scientific studies of recent years, new applicationpossibilities are now being opened up in some areas of biology andmedicine for plasma technology, which has already proved to be a keytechnology for diverse applications of surface treatments in industry([1] M. Laroussi, “Low-Temperature Plasmas for Medicine?”, IEEETransactions on Plasma Science 2009, 37, 714-725; [2] M. Kong et al.,Plasma medicine: “an introductory review”, New Journal of Physics 2009,11, 115012; [3] G. Lloyd et at, “Gas Plasma: Medical Uses andDevelopments in Wound Care”, Plasma Processes and Polymers 2010, 7,194-211).

The potential of plasma technology for applications of this type israted as sufficiently important that an independent discipline known asplasma medicine is now beginning to develop on the international front.One of its substantial objectives, for example, is the development ofinnovative therapeutic methods for treating skin or mucous membranediseases and chronic wounds with cold atmospheric-pressure plasmas, onthe basis of the interaction of antiseptic plasma effect and stimulationof new growth of healthy tissue by the plasma.

In order that plasma-based therapeutic approaches of this type can besystematically developed and employed, suitable plasma sources areneeded that on the one hand work painlessly and ensure that the tissueto be treated is not harmed by temperature, desiccation or electricalvoltages, and on the other hand can be used flexibly for large-areaapplications for various body regions under variable plasma conditions.

Devices for plasma treatment of living tissue with non-thermalatmospheric plasmas have been proposed in several publications (DE3618412 A1, WO 2004/105810 A1, WO 2006/116252 A2). The devices describedin these publications are equipped with rigid electrode systems ornozzles for generation of atmospheric-pressure plasmas in the region ofthe tissue surfaces to be treated, and so they permit only localtreatment of relatively small areas.

OBJECT OF THE INVENTION

The object of the invention was to find a technical solution forgeneration of a superficial plasma that makes it possible to treatrelatively large areas of body parts, especially of arbitrarily curvedareas of human or animal skin or mucous membrane.

OUTLINE OF THE INVENTION

The object is achieved according to the features of the claims.According to the invention, an electrode system for generating adielectric barrier surface discharge is provided that on the one hand iscomposed of flexible materials, so that it can be conformed to curvedsurfaces, and on the other hand has an outer, electrically conductivesurface, which is used as a grounded electrode and is structured in sucha way that dielectric barrier surface discharges can form in theinterstices of the structure that remain open.

A substantial advantage of the invention that is important especiallyfor wound healing is the fact among others that, because of the designas a cuff that conforms to the body, the treated area is covered andthus is protected from desiccation, whereby the moist environmentnecessary according to the prior art for wound healing is better assuredthan during the application of open, rigid electrode systems with a gasflow that may be necessary. The design as a DBD (dielectric barrierdischarge) without or with a small gas flow also counteracts the dangerof desiccation.

A further advantage of the invention is that the elastic electrodesystem can also be configured as a shapeable (inflatable) volume (forexample, as a silicone ball), in such a way that treatments on the onehand of the mucous membrane surfaces of body cavities and on the otherhand of arbitrarily shaped skin or mucous membrane areas can beperformed with the plasma generated on the inner or outer surface ofthis electrode system.

This arrangement offers the possibility of a combination with catheters,endoscopes and surgical instruments. It works both at atmosphericpressure and at slight overpressure or underpressure, with use ofdifferent gases or gas mixtures, if appropriate in combination with thetransport of active substances, and is usable for diverse applicationstoward decontamination, sterilization, antisepsis, wound healing, etc.,both in medicine and in other areas of the life sciences. Slightoverpressure or underpressure means that only minor deviations fromatmospheric pressure are involved here.

Subject matter of the invention is also a method for treating areas ofhuman or animal skin or mucous membrane surfaces by means of a coldatmospheric-pressure plasma. The inventive method consists in the factthat an electrode system of flexible materials for generating adielectric barrier surface discharge is provided, so that it can beconformed to curved surfaces, and that the electrode system has anouter, electrically conductive surface, which is used and structured asa grounded electrode, wherein a dielectric barrier surface discharge isgenerated in the interstices of the structure that remain open.

In a preferred embodiment of the method, it is possible to shape theelastic materials for electrodes and dielectric into a surface with aclosed volume, preferably a silicone balloon, and to ignite a plasmaboth on the inside of the hollow body and on the outside.

EXAMPLES

The invention will be explained in more detail on the basis of figures,without being restricted to these figures.

For this purpose FIGS. 1 and 2 show the basic structure of the inventivedevice. Of those, FIG. 2 is the assembled planar electrode arrangementwhile FIG. 1 represents an exploded view of this arrangement fordemonstration purposes. FIG. 3 shows an exemplary embodiment in curvedform with a gas port for the optional supply of a process gas, and FIG.4 shows an exemplary embodiment of an arm cuff. The basic structure ofan electrode system configured as a shapeable silicone ball isschematically illustrated in FIG. 5, and the application of such aninflatable plasma source for treating the inner surface of body cavitiesin combination with an endoscope is schematically illustrated in FIGS.6a and 6 b.

REFERENCE NUMERAL LIST

The following reference numerals are used for the attached drawings:

-   1 Flexible insulating material (such as elastomer, silicone film)-   2 Flexible high-voltage electrode (such as metal gauze, metal foil,    electrically conductive elastomer)-   3 Flexible dielectric (such as elastomer, silicone film)-   4 Grounded electrode: flexible and structured (such as metal gauze,    structured metal foil, structured electrically conductive elastomer)-   5 Electrical connecting cable-   6 Insulating elastomer with embedded flexible high-voltage electrode-   7 Gas supply-   8 Arm cuff-   9 Balloon of elastic materials (dielectric with embedded electrodes)-   10 Body cavity-   11 Endoscope coupling-   12 Medical strip-   13 Adhesive points-   14 Interstices of the structure that remain open

The invention claimed is:
 1. A device for treatment of areas of human oranimal skin, mucous membrane, or body parts with a coldatmospheric-pressure plasma by generating a dielectric barrier surfacedischarge, comprising: at least one flexible insulating material (1), aplanar flexible high-voltage electrode (2), a planar flexible dielectric(3), a planar flexible grounded electrode (4), a gas supply (7), whereinthe flexible high-voltage electrode (2) is embedded between the at leastone flexible insulating material (1) and the flexible dielectric (3),and wherein the grounded electrode (4) is applied on a surface of theflexible dielectric (3) that faces a curved surface of a body part to betreated, wherein the flexible high-voltage electrode (2), the flexibledielectric (3) and the flexible grounded electrode (4) of the deviceform a flexible layered arrangement for providing the cold atmosphericpressure plasma, wherein said flexible layered arrangement is conformedto be wrapped flexibly around the curved surface of the body part fortreating said curved surface with the cold atmospheric pressure plasmagenerated by the device.
 2. The device according to claim 1, wherein thedevice is a flexible cuff (8) or a medical strip (12).
 3. The flexiblecuff (8) according to claim 2, wherein the cuff (8) represents an arm orleg cuff.
 4. The medical strip (12) according to claim 2, wherein themedical strip (12) has adhesive points (13).
 5. The device according toclaim 1, wherein the device comprises a power-supply unit that isoperatable in pulsed mode of operation and thus offers the possibilityof being able to regulate the intensity of the cold atmospheric pressureplasma within wide limits.
 6. The device according to claim 1, whereinthe grounded electrode (4) is structured as a grid structure, so thatdielectric barrier surface discharges can form in interstices (14) ofthe grid structure that remain open.
 7. The device according to claim 1,wherein metal gauze, metal foil or thin films of metal or conductiveelastomer are used as the flexible high-voltage electrode (2) and/or thegrounded electrode (4).
 8. The device according to claim 1, wherein theflexible high-voltage electrode (2), the flexible dielectric (3) and theflexible grounded electrode (4) of the device are fixed to each other soas to permanently form the flexible layered arrangement for a controlledplasma generation.
 9. The device according to claim 1, wherein theflexible layered arrangement is conformed to be wrapped flexibly aroundthe curved surface of the body part, the body part being a limb, a hand,a finger, or another appendage of the human or animal.